This disclosure is generally directed to imaging members, photoreceptors, photoconductors, and the like. More specifically, the present disclosure is directed to drum, multilayered drum, or flexible, belt imaging members, or devices comprised of a supporting medium like a substrate, a photogenerating layer, and a charge transport layer, including a plurality of charge transport layers, such as a first charge transport layer and a second charge transport layer, and wherein one or more of the charge transport layers contains as an additive or dopant a pyrazine, and a photoconductor comprised of a supporting medium like a substrate, a photogenerating layer, and a charge transport layer which contains an additive or dopant of a pyrazine, and more specifically, a first charge transport layer and a second charge transport layer, and where the charge transport layer includes a pyrazine component that results in photoconductors with a number of advantages, such as in embodiments, desirable light shock reductions; the minimization or substantial elimination of undesirable ghosting on developed images, such as xerographic images, including improved ghosting at various relative humidities; excellent cyclic and stable electrical properties; minimal charge deficient spots (CDS); compatibility with the photogenerating and charge transport resin binders; and acceptable lateral charge migration (LCM) characteristics, such as for example, excellent LCM resistance. At least one in embodiments refers, for example, to one, to from 1 to about 10, to from 2 to about 6; to from 2 to about 4; 2, and the like.
Light shock or light fatigue of photoconductors usually causes dark bands in the resulting xerographic prints caused by the light exposed photoconductor area at time zero, while the photoconductors disclosed herein in embodiments minimize or avoid this disadvantage in that, for example, the light shock resistant photoconductors do not usually print undesirable dark bands even when the photoconductor is exposed to light like office light sources. More specifically, light shock can be caused by the solvent selected for the charge transport layer dispersion, for example, a carbon tetrachloride containing methylene chloride, that is for example, the light shock may in embodiments be caused by carbon tetrachloride or similar contaminated components present in the charge transport layer dispersion, such as methylene chloride. Accordingly, for example, when the charge transport layer coating solvent of methylene chloride contains about 200 parts per million of carbon tetrachloride the light shock value is increased from 1 percent, with no carbon tetrachloride, to 30 percent. This compares to a light shock reduction to, for example, 3 percent when a pyrazine, as illustrated herein, is included in the charge transport layer coating solution.
Also included within the scope of the present disclosure are methods of imaging and printing with the photoconductor devices illustrated herein. These methods generally involve the formation of an electrostatic latent image on the imaging member, followed by developing the image with a toner composition comprised, for example, of thermoplastic resin, colorant such as pigment, charge additive, and surface additives, reference U.S. Pat. Nos. 4,560,635; 4,298,697 and 4,338,390, the disclosures of which are totally incorporated herein by reference, subsequently transferring the image to a suitable substrate, and permanently affixing the image thereto. In those environments wherein the device is to be used in a printing mode, the imaging method involves the same operation with the exception that exposure can be accomplished with a laser device or image bar. More specifically, the imaging members and flexible belts disclosed herein can be selected for the Xerox Corporation iGEN3® machines that generate with some versions over 100 copies per minute. Processes of imaging, especially xerographic imaging and printing, including digital, and/or color printing are thus encompassed by the present disclosure.
The photoconductors disclosed herein are in embodiments sensitive in the wavelength region of, for example, from about 400 to about 900 nanometers, and in particular from about 650 to about 850 nanometers, thus diode lasers can be selected as the light source. Moreover, the photoconductors disclosed herein are in embodiments useful in high resolution color xerographic applications, particularly high-speed color copying and printing processes.